Add 7/20 and 30/21
1st number: 7/20, 2nd number: 1 9/21
7/20 + 30/21 is 249/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
7/20 = 7 × 21/20 × 21 = 147/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
30/21 = 30 × 20/21 × 20 = 600/420 - Add the two like fractions:
147/420 + 600/420 = 147 + 600/420 = 747/420 - 747/420 simplified gives 249/140
- So, 7/20 + 30/21 = 249/140
In mixed form: 1109/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/20+30/21 7/20+60/21 7/40+30/21 7/20+30/42 21/20+30/21 7/20+90/21 7/60+30/21 7/20+30/63 35/20+30/21 49/20+30/21